Let ABC be a triangle. (K) is an arbitrary circle tangent to the lines AC,AB at E,F respectively. (K) cuts BC at M,N such that N lies between B and M. FM intersects EN at I. The circumcircles of triangles IFN and IEM meet each other at J distinct from I. Prove that IJ passes through A and KJ is perpendicular to IJ.Trần Quang Hùng
perpendicularcirclegeometry